perch1
  
  n.
  - a thing on which a bird alights or roosts.
- a high or narrow seat or resting place.
v.
   - alight, sit, or rest on a perch.
- 
(be perched)
 (of a building) be situated above or on the edge of something.
- 
(perch someone/thing on)
 set or balance someone or something on.
Derivative
  
  Etymology
  ME: the noun from perch3; the verb from OFr. percher.
 
  
    
perch2
  
  n.
 (pl. same or perches)
 a freshwater fish with a high spiny dorsal fin, dark vertical bars on the body, and orange lower fins. 
[
Perca fluviatilis (Europe), 
P. flavescens (
yellow perch, N. America), and other species.]
 
▸used in names of similar or related fishes, e.g. climbing perch.
Etymology
  ME: from OFr. perche, via L. from Gk perkē.
 
  
    
perch3
  
  n.
 historical  - a measure of length equal to a quarter of a chain or 5¹⁄₂ yards (approximately 5.029 m).
- 
(also square perch)
 a measure of area equal to 160th of an acre or 30¹⁄₄ square yards (approximately 25.29 sq. metres).
Etymology
  ME (in the sense ‘pole, stick’): from OFr. perche, from L. pertica ‘measuring rod, pole’.